Hey there, I am just using the default brush, and the default start-up scene (so 128x128 canvas).
In the gif I just place down single points randomly and it will randomly act like I dragged it. Lessens when I rotate the mesh after each drawn pixel, but then it randomly skews the "fake line".
Only happens in the mesh view, and not in the uv view.
Happens in both 0.626 and 0.672.
https://streamable.com/fnvnba (A view of the window with the default scene)